Originally Posted by
brandonmarshall
I'm contemplating getting on a plane for an international flight, and I am not very soothed by the claims that planes are by far the safest form of travel, when I find that those claims rely on a "per passenger mile" comparison of various modes of travel. (After all, "per passenger mile", the Space Shuttle is the safest form of transportation, isn't it?)
The Space Shuttles go in big circles, so:
Miles traveled = 0
Deaths > 0
Deaths per passenger mile: +∞
Even if you count miles traveled:
Miles traveled: 446million miles
Deaths: 14
Divide that by 7 people (that's a slight overestimate), so 4.5 deaths per billion passenger miles.
Edit: oops. Forgot passenger miles (divide by 7).
That's much worse than commercial aviation, which is less than 0.5 per billion passenger miles.
Originally Posted by
brandonmarshall
I'd like to know what anyone with a detailed knowledge of the "driving vs. flying" safety statistics thinks about what Mary Schiavo (Former Inspector General of the U.S. Dept. of Transportation) had to say about this in her book "Flying Blind, Flying Safe" (p. 210):
"For years I had heard the FAA excuse planeloads of dead people because the body count for cars was higher in overall numbers. I had found studies and statistics that pointed out that the plane was safer than the car if you compared them on a per mile basis. If you look at them on a per trip basis, the CAR is safer. It only makes sense. It can take thirty or fifty miles for a plane just to get up to cruising altitude, and most car accidents happen less than twenty-five miles from home. Nope, per mile is misleading, slanted, and inaccurate."
Is it really true that "per trip", a car is safer than a plane? If so, how much safer?
The "per trip" safety numbers are the important ones if they apply to your trip; so for the same number of miles and the same number of people. Are "per trip" death stats are defined and computed in a way that that would be significant for comparison for you; i.e. for the SAME trip, the same passenger count (i.e. you)? If so then they're the same as per mile death stats.
Since my trip takes me (a person) a fixed number of miles, it's the chance of my death that matters, so the deaths per passenger mile. Simple.
What if every car manufacturer employee and their family members each "decided" to take 20 extra 0.1mile trips around the block per day? The average per trip deaths for cars in the US would go way down. Would it make your drive any safer? No.